Webs or other sheets of material are used in a variety of industries and in a variety of ways. These materials can include paper, multi-layer paperboard, and other products manufactured or processed in long sheets. As a particular example, long sheets of paper can be manufactured and collected in reels. These sheets of material are often manufactured or processed at high rates of speed, such as speeds of up to one hundred kilometers per hour or more.
It is often necessary or desirable to measure one or more properties of a sheet of material as the sheet is being manufactured or processed. For example, it is often desirable to measure the caliper (thickness) of a paper or other sheet being manufactured to verify whether the sheet's caliper is within certain specifications. Adjustments can then be made to the sheet-making process to ensure that the sheet's caliper stays within a desired range.